1. Field of the Invention
This invention relates to a non-aqueous inkjet ink adapted for use in inkjet recording systems. This invention particularly relates to a non-aqueous inkjet ink containing Brilliant Carmine 6B.
2. Description of the Related Art
Inkjet recording systems have advantages in that an image having a high resolution and good image quality is capable of being printed quickly with low noise and by use of a comparatively cheap apparatus. By virtue of the advantages described above, recently, the inkjet recording systems have quickly become popular. Inks used for the inkjet recording systems are roughly classified into aqueous inks and non-aqueous inks. The non-aqueous inks have the advantages in that on-printer stability, such as intermittent jetting-out performance, or jetting-out recoverability of the inks after being left to stand for a long period of time, is good, in that the inks do not cause the printing paper to be curled, and in that penetration drying time of the inks is short. However, since the non-aqueous inks contain non-volatile solvents, the problems are encountered in that strike through to the back of the paper is apt to occur. In order to improve the strike through, Japanese Unexamined Patent Publication No. 2004-083862 or 2007-277352 proposes addition of silica to the inks.
In the non-aqueous inks, pigments having high solvent resistance are often used. Particularly for magenta color, Brilliant Carmine 6B is often used for its high solvent resistance and its low cost. (For example, reference may be made to Japanese Unexamined Patent Publication No. 2006-083312.)
Therefore, in order to improve the strike through of the magenta color, the inventors conducted extensive research on preparation of inks containing Brilliant Carmine 6B and silica in combination and have found that, though the strike through is improved, the storage stability becomes markedly bad.